Abrading-wheel.



G. N. JEPPSON.

ABRADING WHEBIM APPLIOATION rILnn mmm. 190e.

Patented May 26, .1914.

fn ven for' George /1/ C/qa'on.

COLUMBIA FLANDOIAI'N UnWAlNINTI'ON D.

GEORGE N. JEPPSON, 0F WORCESTER, MASSACHUSETTS.

ABRADING-WHEEL.

Specification of Letters Patent.

Patented May 26, 1914.

Application led February M, 190B. Serial No. 417,332.

To all whom it may concern Be it known that I, GEORGE N. J Errsox, acitizen of thc United States, residing at "oicestclg in the county offrorcester and Commonwealth of Massachusetts, have invented a new anduseful Improvement in .\bradiug-\Vheels, of which the following is aspecification, accompanied by drawings forming a part of the same, inwhich- Figure 1 rc )resents a side view of an abrading wheel embodyingmy invention with a portion of tlie supporting rim broken away. Fig. 2is a face view. Fig. 3 is a central sectional view on the line .f3- 3,Fig. 1. Fig. 4 is a face view showing a modification, and Figs. 5 and 6are detached views of the individual abrading blocks of which the rim ofthe wheel is composed, showing modifications in construction.

Similar reference letters and figures refer to similar parts in thedierent views.

The object of my present invention is to provide what is known as aclearance in that class of composite grinding wheels formed in lpart ofpulverizcd abrading material, suc 1 as emery or corundum and the like,and united in a coherent mass by a suitable bonding material.

A difficulty .frequently arises in the use of wheels of this class owingto the failure of the wheel to clear itself from the detached particlesfrom the body of the wheel or from the work operated on, which, in theoperation of grinding, become embedded in the face of the wheelproducing a glazed surface by the action of pressure and heat, therebygreatly reducing the efiiciency of the wheel. By m present invention, Iobviate this difficulty y providing clearance spaces at fre uentintervals in the grinding surface o the wheel, into which the loosenedparticles may be caught and thrown out by a centrifugal force, insteadof bein dragged over and embedded in the grin ing surface of tho wheel.

In the accompanying drawings I have shown my invention as embodied inthat type of a grinding wheel which consists of an abrasive annulus heldby a central mctallic support, provided with a seat to receive the inneredge of the annulus which is preferably dovetailed and embraced byclamping lips, which securely connect the annu us and its metal support.

' Referring to Figs. 1, 2 and 3 of the drawings 1 denotes a centralcircular metal support, comprising a web 2 and a hub 3 with a series ofradial ribs 4, and provided with a concentric hole 5 for its attachmentto a revolving arbor. The web 2 is enlarged at its periphery to form aseat (3 and is provided with an oblique lip 7. Attached by bolts 8 tothe web 2 is a clamping plate 9 provided with an oblique lip 10correspondmg to the lip T. Arranged around the periphery of the circularmetal support. are a series of abrasive blocks 11, having their inneredges dovetailed at 12 and ada )ted to be clamped between the lips 7 and10 and rest upon the seat 6. which receives the inward thrust of theblocks 11 when pressure is applied to the periphery of the wheel. Theblocks 11 are spaced by the insertion between them of steel spacingplates 13 which are inclosed between the clamping li s 7 and 10. Theinsertion of the spacing p ates 13 between the blocks 11 rovide the openclearance spaces 14, and, y slightly varying the thickness of thespacing plates 13, a solid bearing is secured between the dovetailedbases of the blocks 11.

In the operation of grinding the course of any loosened particles fromeither the wheel or the work which are dragged along the periphery ofthe wheel will be interrupted by tie open spaces 14, allowing them to bethrown off by centrifugal force. The clearance spaces 14 are placedsuiliciently near together to prevent the comminution of the loosenedparticleshy their abrasion against the surface of the wheel and theconsequent glazing of the wheel. The spacing plates 13 are held fromremoval within the clamping lips 7 and 10, but they are short enough toenable the pressure exerted by the bolts 8 to be received by thedovetailed bases 12 of the abrasive blocks. The size of the blocks 11and the thickness of the spacing plates 13 are adapted to the characterof the work to be performed, as well as to the character of the abrasivematerial of which the blocks 11 are composed, as, in some cases, theclearing s aces 14 would require to be wider than in ot 1ers.

In Fig. 4 I have shown a modification, which consists in formingabrasive blocks 15 having their opposing sides at an oblique angle tothe plane of rotation, whereby the clearance s aces 16 extend obliquelyacross the face o the wheel instead of at right angles thereto, as shownin Fig. Q. In Fig. 5 I have shown a detached view of an abrasive block17 having a dovetailed base 12 and adapted to be s )aced by s acingplates 13, as already descri ed. In addition, however, to the c ea'rancespaces formed by spacing plates between the blocks, the block 17 isprovided with a series 0f transverse holes 18, preferably arranged inrows concentric with the wheel.

In operation, as the wheel is worn away, the outer row of holes areeventually worn into and form transverse recesses upon the face of thewheel, and, as the wheel becomes worn below the first row of holes, thesecond or next inner rowof holes are worn into and se on successively asthe wheel is worn away, each successive concentric row of holes 1S inturn forming the transverse recesses on the face of the wheel, intowhich the loosened particles fall and are thrown into by centrifngelforce. i l

In Fig. 6 I have shown a second modification, which consists in forminora block 19 having the dovetailed base 12, xbut having a series of holes2O extending over the outer face 21 toward the inner face of the block,said holes 20 being parallel to facilitate their being formed while theblocks are molded from plastic material to permit the removal of theblocks from the mold.

The employment' of blocks or sections of this, character in theformation of a peripheral abradin .surface furnishes means, in additionto t e slots between the adjacent sections, for preventing the glazingof the peripheral abradin surface of the wheel.

`lie loosened partie es are carried into said holes 20, instead 4ofbeing embedded in the surface of the wheel, and are thrown outwardlytherefrom by centrifugal force.

I claim,

1. In a grinding wheel, the combination, with a central supportingsection provided with peripheral clamping means, of a plurality ofsegmental sections in annular arrangement to provide a peripheralnon-continuous abradm surface, cach of said segmental sections iaving aninner supporting portion emb 'aced by said clamping means, and aplurality of spacing plates, co-extensive with said inner supportingportions and dis oscd in alternating relatlon therewith wit iin saidclamping means, for providing free spaces between said segmentalsections outside of said clamping means.

2. In a grinding wheel, the combination, with a central support-ingsection provided with peripheral clamping means, of a plurality ofsegmental sections of abrasive material forming a peripheral abradingsurface, each of said sections provided with a plurality of holesopening upon said surface, and each of said sections having an innersupporting portion embraced by said clamping means, and a plurality ofspacing plates,` co-extensive with said inner supporting sections anddisposed in alternating relation therewith within said clamping means,whereby to provide free spaces between the said segmental sections onthe peripheral abrading surface formed thereby.

GEORGE il. JEPPSON.

Witnesses:

InNnLorn Comuarusacn, RUrUs B. Fowmm.

Gupte of this patent may be` obtainod for ve cents each, by addressingthe Commissioner ot Patents, Washington, D. 0.

